The present invention relates generally to agricultural machinery and, more particularly, to improvements in balers for harvested crops.
Round balers for bailing agricultural crops have a bale chamber, which is bounded to the side by end-walls and peripherally by bale chamber belts or other drivable winding elements, a supply feed station for feeding-out, via guide rollers, a strip-like covering material for the fully wound round bale, a means controlled by the winding action operation for initiating the feed-out of the covering material, and a cutting device and braking device for controlling the tension of the covering material. The advancing pre-feed roller of said feed-initiating means is preferably coupled to a temporarily detainable blocking element of a blocking device by means of a hub-shaft connection.
In round balers of the aforesaid type, the advancing roller for pulling the covering material from its roll is stationary while the round bale is being formed. The controlled driving means for the advancing roller is switched on after the round bale has been fully wound. The end of the covering material is then transported to the round bale. The speed at which the covering material is moving will increase as the strip-like covering material begins to be carried along by the round bale. This is the reason why the drive means for the advancing roller is equipped with an overrunning clutch. The cutting device for the strip-like material is controlled by the winding action of the covering material. This may be accomplished by means of a counter, which gives a signal when a predetermined number of revolutions of the round bale has occurred following its take-up of the covering material. The signal activates the cutting device. It is necessary for the tension of the strip to be relatively high during the cutting process in order to obtain a clean cut wherein the covering material, which has a difficult-to-cut mesh-like structure, is fully separated from the roll. There should be no braking action during the initial feed-out period of the leading edge of the covering material. The strip should be under no tension or merely subjected to an extremely small amount of tension since only the moments of the rollers have to be overcome. However, in order to ensure that the winding is tight when the covering material is being wound around the round bale by the bale's own rotation, it is necessary for the strip to be adequately tensioned. In certain circumstances, this tension must be significantly increased during the cutting process. The braking devices can be constructed in various ways. Thus, the braking action may be controlled depending on the torque required for driving the advancing roller of the feed-initiating means. A braking device which operates directly on the roll of covering material is also known. Furthermore, it is known to provide a suitably constructed brake for effecting the braking of the strip of covering material, depending on the speed of the covering material.
It is known that to significantly increase the tension in the strip while the covering material is being cut, the advancing roller of the feed-initiating means can be coupled to the blocking element in a blocking device. This blocking element may, for example, be a ratchet wheel that rotates with the roller. Thus, the roller is temporarily halted so that the covering material is pulled over the stationary roller, thereby considerably increasing the tension in the strip.
Although this ensures precise cutting of the strip-like covering material, one cannot prevent the front portion of the severed covering material from adhering to the knife edge in the cutting device. In practice, this amounts to just a few threads. Nevertheless, this may prevent proper feeding of the freely floating leading-edge of the covering material to the round bale during the next winding process. The operation of the system may be impaired due to the improper location of the covering material in the transportation path bounded by the rollers or belts.
There is also the disadvantage that the adjoining components may be subjected to excess loading for a short time. This loading may be extremely high momentarily, when the blocking element comes to a halt.
An object of the present invention is to overcome one or more of the disadvantages described above.
Another object is to produce a simple arrangement for a round baler of the type described herein such that the covering material will hang down in a freely moveable manner after the cutting process.